There are lots of discussion like the current transducer, converter, interface unit, power consumption, and sensor are described in this paper. The following are taken from this paper:

Internet Internet AC Voltage AC Current Pulse Count Measuring Module Internet Interface Unit Temperature Internet Interface Unit Rectifier A/D Converter Address Control Register Amplifier Rectifier Counter Current Transducer Fig. Design Speciﬁcations The main objectives of this project were as follows: to take voltage and current measurements and convert all this analog data into digital data, make temperature measurements, make Watt-hour transducer measurements and send this information to the Internet interface unit.